I finally started stitching this piece yesterday. On Monday, I attached a fairly lightweight cotton wadding with basting spray, and added soluble Vilene, to give it some substance for stitching. I attached the mineral images with basting spray too, instead of fusible webbing, to cut down the thickness but I think perhaps I was a little light with the spray as they don't seem very firmly attached, and I even had to touch up one section with a glue stick to make it hold.
By Tuesday night, I had added most of the darkest darks in the foreground and it looked like this:
Today I added some of the lighter darks and mediums. At this stage, it's still quite brown in the photo but the colours are quite purple and the medium values will be more purple again. I want the yellow of the veins in the rock to stand out vividly from the surrounding rock.